MACKINAC ISLAND -- Michigan Republican Gov. Rick Snyder hasn't formally announced his plans for re-election, but he's certainly building his war chest.

Florida Gov. Jeb Bush, who will join Snyder Wednesday at the Mackinac Policy Conference, on Tuesday met with Republican lawmakers in Lansing, signed copies of his book in West Michigan and wrote on Twitter that he attended a Snyder re-election fundraiser hosted by members of the DeVos family.

Snyder, speaking with MLive on the island Wednesday, acknowledged that he is laying the groundwork for a campaign, but has not made it official.

"I haven't announced I'm running," he said with a smile. "We do have activities such as fundraisers going on, but I'm not formally a candidate yet."

The governor is scheduled to offer opening remarks at the policy conference Wednesday afternoon before handing off the microphone to Bush, who is expected to discuss immigration and education reform. While the Detroit Regional Chamber invited Bush, President and CEO Sandy K. Baruah told MLive that Snyder personally reached out to "bolster the invite."

The fundraiser, as described by Bush, occurred on the same day that former U.S. Congressman and state lawmaker Mark Schauer announced that he will seek the Democratic nomination for governor. He appears to the the party favorite to challenge Snyder in 2014, and very early polls show him running even with the governor, whose approval rates dropped after signing controversial right-to-work legislation late last year.

Snyder's campaign committee remains active and, as of the beginning of the year, had a balance of more than $828,000. Rick Snyder For Michigan spent more than $12 million leading up to the Republican primary and general election in 2010, according to Secretary of State records, including more than $6 million that Snyder and his wife personally loaned the campaign.

Charlie Spies, an attorney with Clark Hill in Washington D.C. who co-founded the Restore Our Future superPAC and previously worked with the Republican Governor's Association, said he expects Michigan's gubernatorial election to be an expensive proposition.

"I wouldn't underestimate Schauer, because he's a good politician and he did relatively well initially in a swing district," he said, referring to the Democrat's 2008 victory over U.S. Rep. Tim Walberg, who repaid the favor two years later. "He's also going to have a tremendous amount of union support from around the country that's going to make attacking (Wisconsin Governor) Scott Walker and Rick Snyder their raison d'être. There will be resources behind him.

"Having said that, you can start to see the results of Governor Snyder's leadership already. And over the next year, they're going to show up even more as the unemployment rate goes down, the economy rebounds and I think Southeast Michigan starts to come back too. All of that will argue for going forward and not moving back."

Jonathan Oosting is a Capitol reporter for MLive Media Group. Email him, find him on Google+ or follow him on Twitter.